LiLo, we must say, we’re proud of you! For once, you managed to avoid a fight with your ex during a major event. Lucky Adam Lambert!

Lindsay Lohan’s on-again/off-again relationship with Sam Ronson is like Groundhog’s Day: big, blow-out public fight, breakup, make up, repeat. But thankfully the 23-year-old starlet avoided her usual pattern in time to help American Idol alum Adam Lambert celebrate his 28th birthday Jan. 29. What a gift!

“Sam was on hand DJ’ing the party, which – of course – led to a visit from Lindsay,” one eyewitness tells HollywoodLife.com exclusively. “Lindsay arrived at the party [held at the Mondrian Hotel’s ADCB lounge in West Hollywood, Calif.] with a guy pal and hung out with Sam and Charlotte Ronson for most of the night. But there was no fighting! She behaved – for once!”

We’re stoked to hear it. Adam – celebrated his big birthday and an even bigger past year – with 100 friends and family including former Guns & Roses rocker Slash and his Idol ‘class-mate’ Anoop Desai.

The very musical crowd sang Adam a heartfelt ‘Happy Birthday’ as he blew out the candles on his cake.

What did you wish for, Adam? Could it be for everyone to forget your controversial AMA’s performance, perhaps?